A System of Permeability Specification for Use in Moisture Simulation Models

Galbraith, G.H.; McLean, R.C.; Guo, Jiansong; Kelly, David J.

doi:10.1177/1420326x9800700406

Cited by 9 publications

(3 citation statements)

References 9 publications

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“…The permeability of samples is measured for determining the normalized flux. Inorder to establish the most appropriate form for the δp(ϕ) function, a methodological study has been conducted using different permeability equations (Galbraith et al, 1998). The regressions are carried out using SPSS 14.0 program and Levenberg-Marquardt algorithm, with no statistically relevant differences observed.…”

Section: Resultsmentioning

confidence: 99%

Application of different transient sorption methods to evaluate moisture diffusion coefficients of building materials on the hygroscopic range

Delgado

Ramos

Freitas

2011

Journal of Building Physics

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Typically, moisture transport coefficients are determined either by stationary measurements, as standard cup set-up and modified cup method, or by dynamic measurements, as the means of the type [Formula: see text] rule in the initial phase of adsorption processes, logarithmic procedure in the end stage of adsorption processes, the half-time method, the moment method, and the hybrid 1-term method. The aim of this work was to test the usability of the five dynamic calculation methods to define the moisture diffusivity in the hygroscopic range of different building materials. The results obtained were compared in order to evaluate the discrepancies between the different calculation techniques. Advantages in time saving using each experimental technique were compared with the feasibility of each process. Two commonly used building materials are considered in the study, gypsum board and gypsum plaster, for adsorptive measurement of the moisture diffusivity at three different temperatures in three different relative humidity ranges.

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Section: Resultsmentioning

confidence: 99%

Application of different transient sorption methods to evaluate moisture diffusion coefficients of building materials on the hygroscopic range

Delgado

Ramos

Freitas

2011

Journal of Building Physics

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“…The regressions are carried out using the Levenberg-Marquardt method, using SPSS 14.0 program. The permeability equation proposed by Galbraith [7] ( )…”

Section: Resultsmentioning

confidence: 99%

Concentration Dependent Diffusion in Building Materials – Application of Different Methods

Ramos

Delgado

Freitas

2008

DDF

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Moisture is an important factor when analyzing the behaviour of building elements and materials. A deeper knowledge on moisture transport under transient conditions of environmental air temperature and humidity is required. In this experimental work, the measurements of moisture diffusion coefficients, w D , of three different types of building materials commonly used in Portugal (gypsum plasterboard, gypsum plaster and gypsum+lime plaster) were obtained for different values of temperature and relative humidity. The results obtained were in good agreement with the values found in literature and show that the increase in temperature resulted in an increase in the diffusion coefficient and an increase in relative humidity (54% to 69%) resulted in a decrease in w D .

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“…3 In addition, a reliable building wall humidity assessment plan must be comprehensive and must provide an effective framework for the long-term planning in the compilation of development plan. 4 Various techniques have been proposed in the literature [5][6][7][8] to predict the building wall humidity level by performing field testing which could be expensive and time consuming as well as using theoretical data based on assumptions. This in turn would affect the accuracy of the developed models in the prediction of humidity level.…”

Section: Introductionmentioning

confidence: 99%

Fuzzy logic-based model for prediction of building wall humidity level

Hossain

Nazir

Ramesh

et al. 2012

Indoor and Built Environment

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This paper presents the viability of using fuzzy logic expert system for the prediction of building wall’s relative humidity. In comparison with traditional logic model, fuzzy logic is more efficient in linking the multiple units to a single output and is invaluable supplements to classical hard computing techniques. The purpose of this work was to investigate the relationship between wall material composition and climate condition, as well as to evaluate the viability of using fuzzy logic expert system in predicting the building wall’s humidity level. The experimental data was taken at different time of the day for different material composition. A fuzzy logic expert system model based on Mamdani approach was subsequently developed to predict the building wall’s humidity level. Verification of the developed fuzzy logic model was carried out through various numerical error criteria. The study revealed that the developed fuzzy system was able to predict the humidity level in the wall material within high accuracy with relative error of less than the acceptable limits of 10% and a goodness of fit very close to unity.

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A System of Permeability Specification for Use in Moisture Simulation Models

Cited by 9 publications

References 9 publications

Application of different transient sorption methods to evaluate moisture diffusion coefficients of building materials on the hygroscopic range

Application of different transient sorption methods to evaluate moisture diffusion coefficients of building materials on the hygroscopic range

Concentration Dependent Diffusion in Building Materials – Application of Different Methods

Fuzzy logic-based model for prediction of building wall humidity level

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